After a much-anticipated breeding, it is hard to wait to find out whether your dog has conceived! The pregnancy diagnosis can be made several ways:
- Palpation (feeling the uterus with the hands)
- Measurement of the hormone relaxin in the blood
- Radiography (x-rays)
Palpation for pregnancy is easiest between 3 – 4 weeks of gestation, however it requires that the female be lean and relaxed. It can only tell whether there is a pregnancy, not whether the puppies are alive or how many there are.
Relaxin is a pregnancy specific hormone that can be easily measured by a simple blood test any time after 28 days. Like palpation, this only confirms pregnancy, not fetal viability or numbers.
Ultrasonography can identify fetal vesicles as early as 17 days gestation, however more information can be obtained at around 4 weeks after the LH peak. At this time the puppies can be seen, and the heartbeats assessed. An estimated count can be made. The fetal sacs can be measured, which can be used to help predict the date of whelping in cases where the date of ovulation is not known.
Radiographs (x-rays): The puppies’ bones start to mineralize after 45 days of gestation. We recommend taking a radiograph one week prior to the anticipated whelp date. At this time the puppies are well mineralized, allowing an accurate count. It also allows assessment of puppy size and position, and gives another technique to estimate the whelp date based on the bones that are visible. It is best performed with an empty stomach and colon, so that the puppies are easier to see. Radiographs are also used after whelping to ensure that no puppies remain.
Behavior: It is not reliable to use physical and behavioral changes as an indicator of pregnancy as these are highly variable signs. Many bitches will have some loss of appetite early in gestation, but some will have an increased appetite. Eventually, weight gain and increased nipple size occur. Late in gestation appetite decreases as the stomach is compressed. Some dogs may become moody or clingy, but others show few behavior changes.